Self-leveling - hold some film on vertical surfaces, but pools evenly across a horizontal plane. Those trends go out the window once used in a sheet metal overlap sandwich, but the quality of conforming evenly in voids between layers and having 'flow-ability' to not lift a layer/section/area proud above others is closer to what the factory used.

U-shaped plate I made to make go around the battery box and create a solid seal around it to the floor with no gaps. The box is going to be for where the shower pan drain's p-trap goes down below the floor level, and the tray is basically a safety for when/if the water heat starts leaking it will drain out off the edge of the floor(the old floor was completely gone around it), but I filled it and fired it up to make sure the water heater was in good working order before going the trouble of installing it again.

Another question. I figured rather than trying to completely fight the water, I'd join it and try and give it a place to go when it does get into certain spots. I thought it would be a good idea to put in some drain holes in the channels around the shell perimeter, and have a part in mind but dont know if such a thing exists. Basically a sleeve with a flange around the top so that I could drill a hole, and drop this guy in so that the water goes down past the plywood and drains out the bottom.

Another question. I figured rather than trying to completely fight the water, I'd join it and try and give it a place to go when it does get into certain spots. I thought it would be a good idea to put in some drain holes in the channels around the shell perimeter, and have a part in mind but dont know if such a thing exists. Basically a sleeve with a flange around the top so that I could drill a hole, and drop this guy in so that the water goes down past the plywood and drains out the bottom.

You have the right idea. One can never completely prevent water from getting into hidden spaces, eg, condensation. However, if you take a look at your C channel I think you'll recognize that it's almost self-draining. There are lots of penetrations from the side from rivets in the lower belt trim and the banana wrap. A C channel might be able to retain 1/4" or so, but the lip on your drain device will probably be 1/8" or more. If you put a 3/4" or even 1/2" drain in multiple places, you'll be inviting insects to build their nests.

I try to be satisfied by not doing things that will trap water, insofar as I have the ability to see the problem ahead of time.

Thanks Andy, but I would like to put the black tank and gray tank under the trailer. My trailer had a Z pattern above. I would like to remanufacture 2 newer one's. I no there are different sites, but I'm wondering is there DIY materials out there?

TxBxSx--LOVING the work you're doing. I was thinking along the same lines with the tray you manufactured. Heck, if it's good enough for my water heater inside my home, it's good enough for my trailer. Keep up the pics and posts. I've got my own baby in the backyard I'm working on a bit at a time. Great Job!

Here is what I did. I made bridges between the C-channels to get rid of the gap between the curved and straight sections. I got some 3/8" stainless tubing with a flare at one end. I just drilled holes where I wanted drains and stuck them in. Zep is correct, the c-channel is self draining but you don't want it to drain into and rot the floor. You want any water to go under the floor and drip out the belly skin. You need to plug and caulk any holes other than the drains. I did this on the right front corner of my trailer and there are no leaks. On the left side it leaks like mad. I have not done this on the left side yet.